Type-2 diabetes is characterized by the presence of insulin resistance, which can also be found in patients with the metabolic syndrome, a precursor of overt diabetes. A recent study in the Journal showed that propofol (Diprivan®) promoted insulin resistance, although it was unclear whether this could be attributed to propofol or the solvent Intralipid®. Myocardial insulin resistance is particularly important as it decreases the tolerance to ischemia/reperfusion injury and increases infarct size.
Dr. Michael Zaugg, Department of Anesthesiology & Pain Medicine, University of Alberta, Edmonton, Canada, and colleagues from the Department of Anesthesia & Pain Medicine and Department of Pharmacology at the University of Alberta, in addition to colleagues at the Department of Clinical Chemistry, University Children’s Hospital, University Hospital Zurich, Zurich, Switzerland, investigated whether propofol, or its solvent Intralipid®, changed glucose utilization in healthy and type-2 diabetic rat hearts. Male Sprague-Dawley rats fed fructose for 6 weeks developed diabetes, and myocardial metabolism was studied in an isolated, working perfused preparation. Their results are published in this month’s issue of Anesthesia and Analgesia and discussed in the article titled “Propofol (Diprivan®) and Intralipid® Exacerbate Insulin Resistance in Type-2 Diabetic Hearts by Impairing GLUT4 Trafficking.”
The investigators undertook a very detailed examination of glucose uptake, glycolysis, and glycogen metabolism with intracellular insulin signaling pathways and myocardial lipids. They concluded that propofol and Intralipid® enhance insulin resistance particularly in type-2 diabetic hearts.
Translation of the results obtained from an isolated rat heart preparation to patients is difficult and the authors do not make any claims about the possible clinical relevance of their findings. However, although a single induction dose of propofol probably has only a transient effect on insulin resistance, the use of prolonged infusions in TIVA and critical care may need to be reconsidered in patients with type-2 diabetes. The researchers have highlighted a potentially important effect of propofol on glucose metabolism.